EP0295236B1 - Hand operated on-off switch with electromagnetic release - Google Patents

Abstract

In a hand-operated on-off switch with an electromagnetic release, a part (9), which opens and closes the switch contacts, and an operating member, particularly a rotating handle (2), are designed so as to be separate and such that they can be coupled together, the part (9), which opens and closes the switch contacts, being loaded from the locked position for the closing movement by a spring. The part (9) and the operating member (2, 6) are designed of material which conducts the magnetic flux, at least on their end surfaces or bearing surfaces (7a, 8a) facing one another, and can be coupled to one another in a force-locked manner by the electromagnet. <??>The coil (10) of the electromagnet can have a voltage applied to it, in this case preferably via auxiliary contacts (16). <IMAGE>

Description

The invention relates to a manually operated on-off switch with electromagnetic release, in which a part that opens and closes the switching contacts and an actuating element, in particular a rotary handle, are designed separately and can be coupled.

Electromagnetic tripping can be an undervoltage trip, a zero voltage trip or a trip as a result of signals, e.g. Temperature signals.

A switch of the type mentioned at the outset, which has a reset device, can be found, for example, in AT-PS 380 973. The coupling of the opening and closing part of the switching contacts with the actuating element takes place in this known switch via a locking plunger which is displaceable in the longitudinal direction of the switch or drive shaft. In order to achieve free tripping, an additional transmission element is provided in this known switch, which is held on a further section of the switch or drive shaft. This further section of the switch or drive shaft is non-rotatably connected to the manually operable part and can be loosely rotated relative to the second area that can be coupled to this part. The switch shaft is taken along via the drivers or the transmission elements connected to them or reset via the plunger and return springs, provided that the electromagnet is energized, since otherwise the transmission elements will not be held in engagement with the elements arranged for the switch-on process can.

The invention now aims to simplify the construction of a manually operated on-off switch of the type mentioned at the outset and to increase the mechanical reliability of such a switch. At the same time, the invention aims to provide the possibility that the switch not only remains in the off position after it has been triggered or switched off, but that the windings of the electromagnet in this off position cannot be unintentionally re-energized.

To achieve this object, the switch according to the invention essentially consists in that the part that opens and closes the switching contacts is loaded by a spring out of the driving position for the closing movement, and that the part that opens and closes the switching contacts and the actuating member at least on their mutually facing end faces or stop faces are formed from the magnetic flux-conducting material and can be non-positively coupled to one another by the electromagnet.

The measure of forming the switching contacts opening and closing part and the actuating member at least on their mutually facing end faces or stop faces made of the magnetic flux-conducting material creates the possibility of coupling these two parts directly to one another by using an electromagnet, whereby naturally, a self-contained magnetic flux must be present without the need for separate mechanical components. After the undervoltage release has taken place, the part that opens and closes the switching contacts and the actuating element are pressed by the springs from the driving position for the closing movement into the open position of the contacts, so that a new coupling of these components is only possible after the two mutually facing end faces have been mechanically approached. An essential feature of the switch according to the invention is the free tripping, ie even when the handle is blocked and the coil circuit in the switched-on state is interrupted, the main contacts are still switched off. This is a security required by many regulations, which ensures that, for example, machines cannot start automatically after a power failure.

In a particularly simple manner, the switch according to the invention is designed in such a way that the switch contacts are designed as an electrically conductive bridge and the part that opens and closes the switch contacts is slidably mounted transversely to the bridge. To switch on, the switch contacts are pulled from the actuator into the closed position, such a positive connection being possible only as long as a magnetic flux is maintained by the facing end faces of the actuator and the part that opens and closes the switch contacts.

In order to prevent current from flowing through the electromagnet when triggering and renewed voltage rise before a new switch-on process is carried out, the design is advantageously made such that the electromagnet can be connected to voltage via auxiliary contacts. These auxiliary contacts should advantageously interrupt the power supply to the electromagnet when the triggering has taken place, and the design can be made in a particularly simple manner so that the auxiliary contacts of the electromagnet with the part that opens and closes the switching contacts and / or the actuating element, in particular by stops , can be coupled.

The coupling of the opening movement of the auxiliary contacts with the opening movement of the switch contacts of the switch can be carried out in a simple manner in that a plunger actuating the auxiliary contacts of the electromagnet is coupled to the actuating element and the auxiliary contacts are in front of the Initiation of the closing movement of the switch contacts closes. The measure of already closing the auxiliary contacts for the electromagnet before the closing movement of the switch contacts of the switch is initiated serves to ensure the magnetic flux through the facing end faces at a point in time at which the end face of the actuator on the end face of the switch contacts opening and closing part is present, so that subsequently closing or switching contacts of the switch is made possible by rotating or pulling the actuator.

A particularly simple and reliable type of coupling of the tappet to the actuating member can be achieved in that the actuating member is in engagement with a rack crossing the axis of rotation of the actuating member. The displacement of this rack when the actuator is rotated enables the desired coupling and offers the possibility of turning the actuator back into the rest position after an undervoltage release. The rack is advantageously coupled with the tappet that actuates the auxiliary contacts. A particularly simple coupling of the movement of the rack with the plunger actuating the auxiliary contacts results from the fact that a pin connected to the plunger is guided in a backdrop of the rack. The rack is advantageously also slidably mounted in its axial direction against the force of a spring in the on position of the actuator. After tripping, the spring presses the toothed rack back into the off position while rotating the actuating member, at the same time the plunger actuating the auxiliary contacts being moved into a position in which the auxiliary contacts of the electromagnet are open. To mechanically relieve the on position from the spring forces, the plunger and the toothed rack can have pawls which, when the switch contacts are in the closed position, are in contact with one another Engage, and it can advantageously be designed spring-loaded itself the plunger actuating the auxiliary contacts of the electromagnet and pressed under the force of the spring into a position in which the auxiliary contacts of the electromagnet are open.

The closed position of the auxiliary contacts of the electromagnet can be secured by an additional projection or stop which interacts with the plunger of the part which opens and closes the switch contacts of the switch. When triggered, this part opens and closes the switching contacts from the actuator under the force of the spring, so that the stop connected to this part is no longer in engagement with the plunger for actuating the auxiliary contacts of the electromagnet and, as a result, this plunger a position can be moved in which the separate switching contacts of the electromagnet are open.

In a particularly simple manner, the actuating element can be designed as a rotary handle which actuates an axially displaceable part via guides which are inclined or helical to the axis of rotation, as a result of which a rotary movement can be converted into an axial displacement of the actuating element, preferably the part which opens and closes the switching contacts for closing the contacts in the axial direction on train and for opening the contacts in the axial direction on pressure is coupled to the actuator.

In a second embodiment of a switch, the procedure is such that the actuating member is designed as a twist grip which actuates a rotatable part via toothings, the part which opens or closes the switching contacts for closing the contacts against the force of a spring upon tension and for opening the contacts on Pressure is coupled to the actuator. The rotary movement of the rotary handle is thus used directly for the switching process, which enables a space-saving construction in the axial direction of the switch.

The invention is explained in more detail below using an exemplary embodiment shown in the drawing.

• Fig. 1 einen Axialschnitt durch einen erfindungsgemäßen Schalter;
• Fig. 2 einen Schnitt nach der Linie II-II der Fig. 1 des Schalters in der Aus-Stellung;
• Fig. 3 einen Schnitt analog zu Fig. 2 des Schalters in der Ein-Stellung;
• Fig. 4 einen Schnitt nach der Linie IV-IV der Fig. 2;
• Fig. 5 eine Ansicht auf die Zahnstange mit dem die Hilfskontakte betätigenden Stößel in vergrößerter Darstellung, wobei Fig. 4 einen Schnitt nach der Linie IV-IV der Fig. 5 darstellt;
• Fig. 6 einen Schnitt nach der Linie VI-VI der Fig. 1;
• Fig. 7 einen Axialschnitt analog zu Fig. 1 durch eine zweite Ausführungsform eines erfindungsgemäßen Schalters;
• Fig. 8 einen Schnitt nach der Linie VIII-VIII der Fig. 7;
• und Fig. 9 einen Schnitt nach der Linie IX-IX der Fig. 7.

In this show:

• 1 shows an axial section through a switch according to the invention;
• Fig. 2 is a section along the line II-II of Figure 1 of the switch in the off position.
• 3 shows a section analogous to FIG. 2 of the switch in the on position;
• Fig. 4 is a section along the line IV-IV of Fig. 2;
• Fig. 5 is a view of the rack with the plunger actuating the auxiliary contacts in an enlarged view, Fig. 4 shows a section along the line IV-IV of Fig. 5;
• Fig. 6 is a section along the line VI-VI of Fig. 1;
• 7 shows an axial section analogous to FIG. 1 through a second embodiment of a switch according to the invention;
• Fig. 8 is a section along the line VIII-VIII of Fig. 7;
• and FIG. 9 shows a section along the line IX-IX of FIG. 7.

1 shows a switch which has a switch housing 1. On this housing 1, a rotary handle 2 is rotatably mounted, which cooperates with a rotatable part 4 via a toothing 3. This part 4 has helical guides 5, as will become clear from the following figures, in which an axially displaceable part 6 engages. The axially displaceable part 6, which cooperates with the actuating element designed as a rotary handle, contains a magnet armature 7, which consists of magnetic flux-conducting material at least in the region of the end faces 7a. At least the area of the end faces 8a of the magnetic yoke 8, which is located in the part 9 that opens and closes the switching contacts, is also made of a magnetic flux-conducting material educated. The parts 6 and 9 or 7 and 8 have recesses in which a coil 10 is arranged, which is arranged in a manner not shown relative to the housing of the switch immovable. Since the end faces 7a and 8a are formed from the magnetic flux-conducting material, it is possible, with the coil switched on, when the rotary handle 2 is actuated and thus a displacement of the part 6 in the direction of the arrow 11, via the part 9 which opens and closes the switching contacts take magnetic coupling between the end faces 7 and 8 and actuate the switching bridges, which are indicated by 12.

2, the switch is shown in the off position. In this view, the helical guide 5 is shown, which causes the axial movement of the part 6 engaging in this helical guide when the rotary handle 2 is rotated. The magnetic parts conducting the magnetic flux 8 or 8a and 7 or 7a are clearly visible in Fig. 2. The opening and closing part 9 of the switching contacts carries electrically conductive bridges 13 each supported by a spring 14. The electromagnet is formed by the magnet armature 7 and magnet yoke 8, which form the closed magnetic circuit, and by the coil 10, which forms the electrical circuit. When the parts 6 and 9 move in the direction of the arrow 11 when the twist grip 2 is turned, a bridge 13 causes the switching contacts 12 to close, as is shown in more detail in FIG. 3. Screws 15 are provided for connecting the switching contacts 12 to lines supplied from the outside and not shown in detail.

With 16 an auxiliary contact is designated, which cooperates with a plunger 17. The auxiliary contact 16 is used to separately apply the coil 10 to voltage. The plunger 17 is supported against the force of a spring 18 and is also moved in the direction of arrow 11 when the twist grip 2 is rotated by a stop or pin 20 which interacts with a toothed rack 19 which interacts with the rotatable part 4. The helical guide 5 of the rotatable part 4 is hiebei almost normal in the first portion to the axial direction 21 of the switch, which makes it possible that the tappet 17 at the beginning of the drive through the rack, as will be explained in more detail below Rotary movement of the rotary handle 2 first closes the auxiliary contact 16 and thus excitation of the electromagnet is caused, whereupon the part 6 is displaced in the direction of arrow 11 when the rotary handle is rotated further. Since current is already flowing through the coil 10 at this point in time, a non-positive coupling results between the parts 7 and 8 formed from the magnetic flux-conducting material, which enables the contacts 12 to be closed.

In Fig. 3 the switch according to the invention is shown in the on position. The spring 14 presses on the electrically conductive bridge 13 and thus gives the contact pressure for a safe current transfer. The support of the electrically conductive bridge 13 via a spring 14 makes it possible to compensate for unevenness or level differences between the individual switching contacts 12. In the position of the switch according to the invention shown in FIG. 3, the plunger 17 is secured by a stop 22 on the part 9 that opens and closes the switch contacts. The fact that the plunger 17 is acted upon by a spring 18 ensures that the auxiliary contact 16 leading to the coil 10, which is pretensioned to close the contact, is opened when triggered by the electromagnet or when switched off.

4 shows in more detail how the rack 19 interacts with the rotary handle. The rotatable part 4 has a toothing 23 which cooperates with a toothing 24 of the rack. When the part 4 is rotated in the direction of the arrow 25, the toothed rack 19 is moved in the direction of the arrow 27 against the force of a spring 26.

As shown in FIG. 5, the rack 19 has a link in a partial area, in which the pin 20 of the plunger 17 engages. When the toothed rack moves in the direction of arrow 27, the plunger is displaced in the direction of arrow 11, thereby closing the auxiliary contact 16 and thus exciting the electromagnet, as described above. However, if there is no voltage on the supply side of the switch, the electromagnet cannot be activated and the part 9 opening and closing the switch contacts cannot be taken along when the twist grip 2 is turned further. If, on the other hand, the electromagnet is energized, the contacts will close via the frictional coupling between parts 7 and 8, and the plunger 17 will also counteract the force of spring 18 via stop 22 of part 9 in which the switching contacts open and close held in his depressed position. To relieve the spring forces in the on position, the plunger 17 and the rack 19 have pawls 28 and 29, which come into engagement with one another in the closed position of the switching contacts. In the closed position of the switching contacts, the pin 20 of the plunger 17 is in the position shown in dashed lines in FIG. 5 within the link path 30.

From Fig. 6 it can be seen that the part 9 is acted upon by springs 32, which can be supported, for example, on the coil 10, which when triggered by the Electromagnets open the switching bridge and thus interrupt the main circuit.

The process of tripping, for example by undervoltage, a reduction in the magnetic force, a voltage failure or by an interruption of the circuit, which results in the loss of the magnetic force, is briefly explained below. Starting from the closed position shown in Fig. 3, i.e. If the switch is in the on position, it should be triggered by the electromagnet. If the magnetic flux induced by the electromagnet in sections 7 and 8 is lowered or completely disappears, the force on the end faces 7a and 8a decreases and the force of the spring 32 makes the part 9 opposite to the direction of the arrow 11 moves, which opens the switch contacts. At the same time, the plunger 17 loaded by the spring 18 moves in the opposite direction of the arrow 11, since the plunger 17 is no longer held in the depressed position by the stop 22 of the part 9. This movement results in the auxiliary contact 16 being opened, as a result of which the current flow through the coil 10 is interrupted. As can be seen from FIGS. 4 and 5, with this movement of the plunger 17, the locking of the pawls 28 and 29 is also released and the rack 19 is moved against the direction of arrow 27 by the force of the spring 26. This movement of the rack 19 also causes a movement of the rotary handle 2 into the off position via the toothings 23 and 24. Since, in this end position, after the triggering, the plunger is also in its initial position, the auxiliary contact 16 is securely opened, and the coil 10 cannot be unintentionally re-energized.

An essential feature of the switch according to the invention is the free trip, ie even when switched on If the handle is blocked and the coil circuit is interrupted, the main contacts are still switched off. This is a security required by many regulations, which ensures that, for example, machines cannot start automatically after a power failure. A new on-switching process can thus only be carried out by actuating the rotary handle 2, it being necessary to ensure that the coil 10 can be connected to voltage via the auxiliary contact 16 in order to achieve a coupling between the parts 6 and 9. The part 9 opening and closing the switching contacts is coupled to the part 6 for closing the contacts 12 in the direction of the arrow 11 against the force of the springs 32, while for opening the contacts against the direction of the arrow 11 when the rotary handle is actuated, a coupling Printing takes place.

7 to 9, a second embodiment of a switch according to the invention is shown. In turn, a rotary handle 2 is rotatably mounted on a housing 1 and is coupled to a rotatable part 34 via the interposition of a rotatable part 33. The part 34 is formed in the region of its end face or stop face 35 from the magnetic flux-conducting material, as is the end face or stop face 36 of a rotatable part 37. The parts 34 and 37 have recesses in their interior for receiving a coil 10 on. With 38 a spiral spring is indicated, by which the opening and closing of the switching contacts 37 is loaded out of the driving position for the closed position shown in FIG. 7. The part 37 is coupled to a cam 55 via a plug-in profile and this actuates the plungers 39 via the plunger 39, which are supported by springs 41, the cam performing a rotating movement, the plunger 39 and switching bridges 40 performing a linear movement. The part 37 has a stop 42 which holds a plunger interacting with an auxiliary contact 43 in the closed position. The Tappet 44 is again acted upon by a spring 45 and is moved by a toothed rack 46, which is loaded by the force of a spring 47, as will be described in more detail below.

8 shows a section in the region of the end faces or stop faces 35 and 36. When the rotary handle 2 moves, the stop surfaces 35, which are connected to the part 34, are rotated in the direction of the arrow 48. If the coil 10 has been energized by closing the auxiliary contact 43 at the start of the rotary movement of the rotary handle 2, this takes place due to the induced magnetic flux when the stop surfaces 35 move in the direction of arrow 48, the stop surfaces 36 of the part 37 that opens and closes the switch contacts. The part 37 that opens and closes the switch contacts is also in this embodiment, counter to the force of the spiral spring 38 loaded when the contacts close on train, while a load by pressing the stop surfaces 35 on the surfaces 36 against the direction of arrow 48 is effective when switching off.

The plunger 44 is actuated to close the auxiliary contact during the rotary movement of the rotary handle 2 in a manner similar to that in the first exemplary embodiment of the switch according to the invention (FIG. 9). The toothed rack 46 is moved via toothings 49, 50 in the direction of arrow 51 against the force of the spring 47. A pin 52 arranged on the tappet 44 is in turn guided in a slide track of the toothed rack, which is similar to the embodiment shown in FIG. 5 . The rack 46 and the plunger 44 in turn have pawls 53 and 54, which come into engagement with one another when the switch contacts are closed and relieve the spring force.

The electromagnetic triggering of this second embodiment of the switch according to the invention takes place in a manner similar to that of the first embodiment. If the magnetic flux induced by the coil 10 in the end or stop surfaces 35 and 36 of the rotatable parts 34 and 37 drops or disappears, the part 37 is rotated counter to the direction of the arrow 48 by the force of the spring 38 the stop 42 comes out of engagement with the plunger 44, which moves by the force of the spring 45 in the direction of the auxiliary contact 43 and opens it. During this movement, the pawls 53 and 54 disengage at the same time, as a result of which the toothed rack is displaced in the direction opposite the arrow 51 and rotates the rotary handle into the off position via the toothings 49 and 50. As has already been explained in detail above, in this embodiment too, a renewed switching on can only be effected by turning the rotary handle 2, since the electromagnet cannot be energized.

Since the opening and closing part of the switching contacts is loaded in both embodiments by a spring from the driving position for the closing movement, the coupling between the stop and / or End faces, whereby the switch contacts are opened. The switch according to the invention can only be switched on when the electromagnet can be put under voltage by closing the auxiliary contacts and thus a non-positive coupling between the actuating member and the part that opens and closes the switching contacts is made possible. After an electromagnetic release, the switch is automatically brought into its off position and the windings of the electromagnet in this off position cannot be unintentionally re-energized.

Claims (15)

1. Hand-operable on-off switch with electromagnetic release, in which a part (9, 37), opening and closing the switching contacts (12), and an operating element, in particular a twist grip (2), are formed separately and in such a way that they can be coupled, characterised in that the part (9, 37) opening and closing the switching contacts (12) is loaded by a spring (18, 32, 38) out of the driving position for the closing movement, and in that the part (9, 37) opening and closing the switching contacts and the operating element (2, 6, 34) are formed, at least on their mutually facing end faces or stop faces (7a, 8a, 35, 36), from material conducting the magnetic flux and are able to be coupled frictionally to each other by the electromagnet (7, 8, 35, 36; 10).
2. Switch according to claim 1, characterised in that the switching contacts are formed as an electrically conducting bridge (13, 40) and the part (9, 37) opening and closing the switching contacts is displaceably mounted transversely with respect to the bridge.
3. Switch according to Claim 1 or 2, characterised in that the electromagnet (7, 8, 35, 36; 10) can be connected to voltage via auxiliary contacts (16, 43).
4. Switch according to Claim 3, characterised in that the auxiliary contacts (16, 43) of the electromagnet are able to be coupled to the part (9, 37) opening and closing the switching contacts and/or to the operating element (2, 6, 34), in particular by stops.
5. Switch according to Claim 3 or 4, characterised in that a tappet (17, 42), operating the auxiliary contacts (16, 43) of the electromagnet, is coupled to the operating element (2, 6, 34) and closes the auxiliary contacts before the initiation of the closing movement of the switching contacts.
6. Switch according to one of Claims 1 to 5, characterised in that the operating element (6, 34) is in engagement with a toothed rack (19, 46) crossing the axis of rotation (21) of the operating element.
7. Switch according to Claim 6, characterised in that the toothed rack (19, 46) is coupled to the tappet (17, 42) operating the auxiliary contacts (16, 43).
8. Switch according to Claim 6 or 7, characterised in that a pin (20, 52), connected to the tappet (17, 42), is guided in a slotted link (30) of the toothed rack (19, 46).
9. Switch according to Claim 6, 7 or 8, characterised in that the toothed rack (19, 46) is mounted displaceably in its axial direction against the force of a spring (26, 47) into the on position of the operating element (2, 6, 34).
10. Switch according to one of Claims 5 to 9, characterised in that the tappet (17, 42) operating the auxiliary contacts (16, 43) of the electromagnet is of a spring-loaded design and is pressed under the force of the spring (18, 45) into a position in which the auxiliary contacts of the electromagnet are open.
11. Switch according to one of Claims 5 to 10, characterised in that the tappet (17, 42) and the toothed rack (19, 46) have catches (28, 29; 53, 54), which come into engagement with one another in the closed position of the switching contacts.
12. Switch according to one of Claims 5 to 11, characterised in that the closing position of the auxiliary contacts (16, 43) of the electromagnet is secured by an additional projection or stop (22, 42), interacting with the tappet (17, 42), of the part (9, 37) opening and closing the switching contacts of the switch.
13. Switch according to one of Claims 1 or 12, characterised in that the operating element is designed as a twist grip (2), which operates an axially displaceable part (6) by means of guides (4) oblique to the axis of rotation (21) or helically shaped.
14. Switch according to Claim 131 characterised in that the part (9) opening or closing the switching contacts is coupled to the operating element for closing the contacts in the axial direction by tension and for opening the contacts in the axial direction by compression.
15. Switch according to one of Claims 1 to 12, characterised in that the operating element is formed as a twist grip (2), which operates a rotatable part (33, 34) by means of toothings, the part (37) opening or closing the switching contacts being coupled to the operating element for closing the contacts against the force of a spring (38) by tension and for opening the contacts by compression.

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